Replace the local reference counting by already available mechanisms
offered by kref. Where possible existing device structures were used,
including the same functionality.
Signed-off-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

The global config_lock was used to protect the configuration organized
in independent lists. It is not necessary to have a lock on driver
level for this purpose.  This patch replaces the global config_lock
with a set of local list locks.
Signed-off-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

Adapt the change_queue_depth callback in zfcp for the new reason
parameter. Simply pass each call back to the SCSI midlayer, there are
no resource adjustments necessary for zfcp.
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>

Removes check for (depth <= default_depth) in case of
SCSI_QDEPTH_RAMP_UP call back, not needed after added
max_queue_depth per sdev.
Signed-off-by: NVasu Dev <vasu.dev@intel.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

This patch modifies scsi_host_template->change_queue_depth so that
it takes an argument indicating why it is being called. This will be
used so that if a LLD needs to do some extra processing when
handling queue fulls or later ramp ups, it can do so.

This is a simple port of the drivers setting a change_queue_depth
callback. In the patch I just have these LLDs adjust the queue depth
if the user was requesting it.
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>

[Vasu.Dev: v2
	Also converted pmcraid_change_queue_depth and then verified
all modules compile  using "make allmodconfig" for any new build
warnings on X86_64.

	Updated original description after combing two original
patches from Mike to make this patch git bisectable.]
Signed-off-by: NVasu Dev <vasu.dev@intel.com>
[jejb: fixed up 53c700]
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

When configuring a LUN for use in zfcp, flush the SCSI work to ensure
the SCSI device has been created before returning. This means that a
configuration procedure can run these commands in a script and the
SCSI device is available immediately after the unit_add:

echo 1 > /sys/bus/ccw/drivers/zfcp/0.0.181d/online
echo 0x401040C300000000 > \
        /sys/bus/ccw/drivers/zfcp/0.0.181d/0x500507630313c562/unit_add
lsscsi
Reviewed-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

Add HZ since the start_timer function expects jiffies, not seconds.
Reviewed-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

After opening a remote port zfcp checks if the WWPN returned in the
PLOGI maches the WWPN of the port that should have been opened. On a
mismatch zfcp assumes that the DID just changed, queries the FC
nameserver and tries again. If the situation persists the erp will
give up.

With this strategy, if the remote port always returns the wrong PLOGI
data, the remote port will not be opened. Introduce a warning, so that
the system administrator knows why the remote port is not being opened
and to have a pointer to investigate the problem on the storage
system.
Reviewed-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

For ports, zfcp gets the DID from the FC nameserver and tries to open
the port. If the open succeeds, zfcp compares the WWPN from the
nameserver with the WWPN in the PLOGI payload. In case of a mismatch,
zfcp assumes that the DID of the port just changed and we opened the
wrong port. This means that zfcp has to forget the DID, lookup the DID
again and retry.

This error case had a problem that zfcp forgets the DID, but never
looks up a new one, stalling the ERP in this case. Fix this by
triggering the DID lookup and properly exit from the ERP. The DID
lookup will trigger a new ERP action.

Also ensure when trying to open the port again with the new DID, first
close the open port, even in the NOESC case.
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

The pointer that is allocated with kmalloc() is passed to strsep()
which modifies it. Later on the modified pointer value will be passed
to kfree. Save the original pointer and pass that one to kfree
instead.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

Fix this build error:

	next-20091013 randconfig build on s390x build breaks with

drivers/s390/built-in.o:(.data+0x3354): undefined reference to `sclp_vt220_pm_event_fn'
Reported-by: NKamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Signed-off-by: NMichael Holzheu <michael.holzheu@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Use cio_is_console() in io_subchannel_probe to indicate that the
special handling is console specific. As long as there is no other
subchannel for which this might be true, it is misleading to speak
of "early devices". Should more of these devices be introduced,
a cleanup of all console special handling is in order anyway.
Signed-off-by: NPeter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

8d65af78 "sysctl: remove "struct file *" argument of ->proc_handler"
removed the struct file argument from all proc_handlers but didn't
change the call home proc handler (or call home was merged later).

So fix this now.

Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Hans-Joachim Picht <hans@de.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

If the rdc_buffer is above 2G we need indirect addresssing so we have
to use an idaw to give the rdc_buffer to the ccw.
If the rdc_buffer is under 2G nothing changes.
Signed-off-by: NStefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Replace spin_lock with spin_lock_irqsave in dasd_eckd_restore_device.
Signed-off-by: NStefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

When setting a channel attached tape online under Linux 2.6.31, the

"vol_id" process from udev hangs in sync_page():
 2 sync_page+144 [0x1dfaac]
 3 __wait_on_bit_lock+194 [0x58c23e]
 4 __lock_page+116 [0x1df9dc]
 5 truncate_inode_pages_range+728 [0x1ed7cc]
 6 __blkdev_put+244 [0x25f738]
 7 __fput+300 [0x229c4c]
 8 filp_close+122 [0x225a3a]

The reason for that is an error in the request queue handling. It can
happen that we fetch a request, but do not process it further because
the number of queued requests exceeds TAPEBLOCK_MIN_REQUEUE.
To fix this, we should call blk_peek_request() instead of
blk_fetch_request() in the while condition and fetch the request in
the loop body afterwards.

This bug was introduced with the patch "block: implement and enforce
request peek/start/fetch" (9934c8c0)
Signed-off-by: NMichael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

There is a race while re-reading the device characteristics. After
cleaning the memory area a cqr is build which reads the device
characteristics. This may take a rather long time and the device
characteristics structure is zero during this. Now it could be
possible that the block tasklet starts working and a new cqr will be
build. The build_cp command refers to the device characteristics
structure and this may lead into a divide by zero exception.
Fix this by re-reading the device characteristics into a temporary
structur and copy the data to the original structure. Also take the
ccwdev_lock.
Signed-off-by: NStefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Improve the comments for switch cases without a break. This fixes
some warnings of a code checker tool.
Signed-off-by: NFelix Beck <felix.beck@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Do not shadow earlier symbol.
Signed-off-by: NFelix Beck <felix.beck@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Allow users to set boxed devices offline. After setting them
offline, the device state will still be boxed.
Signed-off-by: NPeter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

When a ccw device appears not operational, inform the associated
device driver and act according to the response: if the driver
wants to keep the device, put it into the disconnected state.
If not, or if there is no driver or if the device is not online,
unregister it. This approach is consistent with no-path event
handling.
Signed-off-by: NPeter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

When there is no path left to a ccw device, inform the associated
device driver and act according to the response: if the driver
wants to keep the device, put it into the disconnected state.
If not, or if there is no driver or if the device is not online,
unregister it.
Signed-off-by: NPeter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

There is a memory leak in /proc/cio_ignore. The iterator is allocated
in cio_ignore_proc_seq_start, but never freed in
cio_ignore_proc_seq_stop, because we cannot use the iterator
that was passed by seqfile. The seqfile interface passes the last
seen iterator to the stop function and not the first one. Since our
next function will return NULL at the end, the iter passed to
cio_ignore_proc_seq_stop is NULL. The original iter has leaked.
The solution is to use seq_open_private.

Found with kmemleak:
unreferenced object 0x1c720580 (size 32):
  comm "head", pid 973, jiffies 4294958302
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 04 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<0000000000203154>] kmem_cache_alloc+0x190/0x19c
    [<00000000003fb462>] cio_ignore_proc_seq_start+0x5e/0x128
    [<0000000000231018>] seq_read+0xc8/0x4bc
    [<0000000000273954>] proc_reg_read+0xa8/0xf4
    [<000000000020e3d8>] vfs_read+0xac/0x1a4
    [<000000000020e5c6>] SyS_read+0x52/0xa8
    [<000000000011836e>] sysc_noemu+0x10/0x16
    [<0000004690b7936c>] 0x4690b7936c
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Move dev_set_name to when we know that the device will actually be
registered in order to avoid a memory leak if the allocated memory
for the channel path has to be freed.
Signed-off-by: NMichael Ernst <mernst@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Fix this build failure:
drivers/s390/built-in.o: In function `raw3270_pm_unfreeze':
(.text+0x3ac04): undefined reference to `ccw_device_force_console'
with:
CONFIG_TN3270=y
CONFIG_TN3270_CONSOLE=n
CONFIG_TN3215_CONSOLE=n
Reported-by: NKamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Running chchp --vary 0 and chccwdev -d on a FCP device with scsi
devices attached can lead to this thread hanging:

================================================================
STACK TRACE FOR TASK: 0x2fbfcc00 (kslowcrw)

 STACK:
 0 schedule+1136 [0x45f99c]
 1 schedule_timeout+534 [0x46054e]
 2 wait_for_common+374 [0x45f442]
 3 blk_execute_rq+160 [0x217a2c]
 4 scsi_execute+278 [0x26daf2]
 5 scsi_execute_req+150 [0x26dc86]
 6 sd_sync_cache+138 [0x28460a]
 7 sd_shutdown+130 [0x28486a]
 8 sd_remove+104 [0x284c84]
 9 __device_release_driver+152 [0x257430]
10 device_release_driver+56 [0x2575c8]
11 bus_remove_device+214 [0x25672a]
12 device_del+352 [0x25456c]
13 __scsi_remove_device+108 [0x272630]
14 scsi_remove_device+66 [0x2726ba]
15 zfcp_ccw_remove+824 [0x335558]
16 ccw_device_remove+62 [0x2b3f2a]
17 __device_release_driver+152 [0x257430]
18 device_release_driver+56 [0x2575c8]
19 bus_remove_device+214 [0x25672a]
20 device_del+352 [0x25456c]
21 ccw_device_unregister+92 [0x2b48c4]
22 io_subchannel_remove+108 [0x2b4950]
23 css_remove+62 [0x2af7ee]
24 __device_release_driver+152 [0x257430]
25 device_release_driver+56 [0x2575c8]
26 bus_remove_device+214 [0x25672a]
27 device_del+352 [0x25456c]
28 device_unregister+38 [0x25464a]
29 css_sch_device_unregister+68 [0x2af97c]
30 ccw_device_call_sch_unregister+78 [0x2b581e]
31 worker_thread+604 [0x69eb0]
32 kthread+154 [0x6ff42]
33 kernel_thread_starter+6 [0x1c952]
================================================================

The problem is that the chchp --vary 0 leads to zfcp first calling
fc_remote_port_delete which blocks all scsi devices on the remote
port. Calling scsi_remove_device later lets the sd driver issue a
SYNCHRONIZE_CACHE command. This command stays on the "stopped" request
requeue because the SCSI device is blocked. Fix this by first removing
the scsi and fc hosts which removes all scsi devices and do not use
scsi_remove_device.
Reviewed-by: NFelix Beck <felix.beck@de.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

=======================================================
[ INFO: possible circular locking dependency detected ]
2.6.31-39.x.20090917-s390xdefault #1
-------------------------------------------------------
kslowcrw/83 is trying to acquire lock:
 (&adapter->scan_work){+.+.+.}, at: [<0000000000169c5c>] __cancel_work_timer+0x64/0x3d4

but task is already holding lock:
 (&zfcp_data.config_mutex){+.+.+.}, at: [<00000000004671ea>] zfcp_ccw_remove+0x66/0x384

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (&zfcp_data.config_mutex){+.+.+.}:
       [<0000000000189962>] __lock_acquire+0xe26/0x1834
       [<000000000018a4b6>] lock_acquire+0x146/0x178
       [<000000000058cb5a>] mutex_lock_nested+0x82/0x3ec
       [<0000000000477170>] zfcp_fc_scan_ports+0x3ec/0x728
       [<0000000000168e34>] worker_thread+0x278/0x3a8
       [<000000000016ff08>] kthread+0x9c/0xa4
       [<0000000000109ebe>] kernel_thread_starter+0x6/0xc
       [<0000000000109eb8>] kernel_thread_starter+0x0/0xc

-> #0 (&adapter->scan_work){+.+.+.}:
       [<0000000000189e60>] __lock_acquire+0x1324/0x1834
       [<000000000018a4b6>] lock_acquire+0x146/0x178
       [<0000000000169c9a>] __cancel_work_timer+0xa2/0x3d4
       [<0000000000465cb2>] zfcp_adapter_dequeue+0x32/0x14c
       [<00000000004673e4>] zfcp_ccw_remove+0x260/0x384
       [<00000000004250f6>] ccw_device_remove+0x42/0x1ac
       [<00000000003cb6be>] __device_release_driver+0x9a/0x10c
       [<00000000003cb856>] device_release_driver+0x3a/0x4c
       [<00000000003ca94c>] bus_remove_device+0xcc/0x114
       [<00000000003c8506>] device_del+0x162/0x21c
       [<0000000000425ff2>] ccw_device_unregister+0x5e/0x7c
       [<000000000042607e>] io_subchannel_remove+0x6e/0x9c
       [<000000000041ff9a>] css_remove+0x3e/0x7c
       [<00000000003cb6be>] __device_release_driver+0x9a/0x10c
       [<00000000003cb856>] device_release_driver+0x3a/0x4c
       [<00000000003ca94c>] bus_remove_device+0xcc/0x114
       [<00000000003c8506>] device_del+0x162/0x21c
       [<00000000003c85e8>] device_unregister+0x28/0x38
       [<0000000000420152>] css_sch_device_unregister+0x46/0x58
       [<00000000004276a6>] io_subchannel_sch_event+0x28e/0x794
       [<0000000000420442>] css_evaluate_known_subchannel+0x46/0xd0
       [<0000000000420ebc>] slow_eval_known_fn+0x88/0xa0
       [<00000000003caffa>] bus_for_each_dev+0x7e/0xd0
       [<000000000042188c>] for_each_subchannel_staged+0x6c/0xd4
       [<0000000000421a00>] css_slow_path_func+0x54/0xd8
       [<0000000000168e34>] worker_thread+0x278/0x3a8
       [<000000000016ff08>] kthread+0x9c/0xa4
       [<0000000000109ebe>] kernel_thread_starter+0x6/0xc
       [<0000000000109eb8>] kernel_thread_starter+0x0/0xc

cancel_work_sync is called while holding the config_mutex. But the
work that is being cancelled or flushed also uses the config_mutex.
Fix the resulting deadlock possibility by calling cancel_work_sync
earlier without holding the mutex. The best place to do is is after
offlining the device.  No new port scan work will be scheduled for the
offline device, so this is a safe place to call cancel_work_sync.
Reviewed-by: NFelix Beck <felix.beck@de.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

With the change that the zfcp_adapter struct is only allocated when
the device is set online, the shutdown handler has to check for a
non-existing zfcp_adapter struct. On the other hand, this check is not
necessary in the offline callback, since an online device has the
zfcp_adapter allocated and we go through the offline callback before
removing the ccw device.
Reviewed-by: NFelix Beck <felix.beck@de.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

With the change for delaying the allocation of zfcp_adapter, the
initial device parameter function has to first call
ccw_device_set_online which allocates the zfcp_adapter structure.
Change this and adapt the cfdc part accordingly.
Reviewed-by: NFelix Beck <felix.beck@de.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

The common initialization of ct/gs and els requests missed the
initialization of unchained requests. Fix this by moving the common
parts to a place that is called for all ct/gs and els requests.
Reviewed-by: NFelix Beck <felix.beck@de.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

[akpm@linux-foundation.org: fix KVM]
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Acked-by: NMike Frysinger <vapier@gentoo.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

* remove asm/atomic.h inclusion from linux/utsname.h --
   not needed after kref conversion
 * remove linux/utsname.h inclusion from files which do not need it

NOTE: it looks like fs/binfmt_elf.c do not need utsname.h, however
due to some personality stuff it _is_ needed -- cowardly leave ELF-related
headers and files alone.
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The DASD device driver reads the feature codes of a device during
device initialization. These codes are later used to determine the
availability of advanced features like PAV or High Performance FICON.
Some very old devices do not support the command to read feature
codes and the initialization routine fails.
As the feature codes are not necessary for basic DASD operations, we
can support such devices by just ignoring missing feature codes.
Signed-off-by: NStefan Weinhuber <wein@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Devices are no longer removed or added in the suspend and resume
callbacks. Instead they are marked unregistered in suspend. In the
resume callback the ap_scan_bus method is scheduled. The bus scan
function will remove the old device and add new ones. This way all
the device handling will be done in only one function. Additionaly
the case where the domain might change during suspend/resume is
caught. In that case the devices qid needs to re-calculated in
order of having it found by the scan method.
Signed-off-by: NFelix Beck <felix.beck@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

If input buffers stay in primed state qdio may not receive further interrupts
for the input queue depending on the firmware. That can cause a connection
hang on OSA cards.

Change the state of all primed input buffers that are not acknowledged to
not initialized.
Signed-off-by: NJan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Even if turned off the debug message overhead is measurable in the hot path.
Reduce the number of debug message calls in do_QDIO and qdio_kick_handler.
Also use hex numbers to save space in the debug entries.
Signed-off-by: NJan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Previously, there were multiple subchannel scanning mechanisms
which could potentially conflict with each other. Fix this problem
by moving blacklist and ccw driver triggered scanning to the
existing evaluation method.
Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The functions idset_sch_new and for_each_subchannel_staged
use different values for the number of subchannel sets. Make
it consistent by changing idset_sch_new to also use the actual
number of subchannel sets.
Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Don't use kfree to free memory allocated by vmalloc.
Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Introduce the css_driver callback settle which can be implemented
by a subchannel driver to wait for the subchannel type specific
asynchronous work to finish.
In channel_subsystem_init_sync we call that for each subchannel
driver.
Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Use css_eval_scheduled to determine if all scheduled subchannel
evaluation is finished. Wait for this value to be 0 in the
channel subsystem init function.
Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>